@media all and (max-width: 1100px) {
    body { 
      grid-template-areas: 
        "header"
        "nav"
        "ads"
        "article"
        "footer";
      grid-template-rows: 80px 1fr 60em 40em 70px;  
      grid-template-columns: 1fr;
   }
   #mainNav { 
    grid-area: nav;
    display: flex;
    flex-direction: row; 
    }
  }